Prior to the present invention, there have existed a number of different types of film reels having various configurations in the core structures for the threading and retaining of the mountable end of a film to be reeled onto the reel. Typical ones of such patents are as follow. There is Taesler et al. U.S. Pat. No. 3,351,298 granted Nov. 7, 1967 in which a movable wedge-post may be turned within threading space in order to wedge the film in a vise-like manner against an inner surface of the outer wall structure of the core. Also, there is the Hertel U.S. Pat No. 3,746,204 in which the inner core has an outwardly extending projection against which all of the film being wound on the core presses thereagainst in order to secure the loose end of the film being wound onto the reel, being granted July 3, 1973. Also there is Grant U.S. Pat. No. 3,675,869 granted July 11, 1972 which discloses a core's radially-extending wall having transverse spaced-apart grooves therein through which the ends of the film is threaded through one and then sequentially through another one thereof. Also there is Fujiwara et al. U.S. Pat. No. 3,648,944 granted Mar. 14, 1972 discloses a core free-space having a loose cylindrical member which when a film is wrapped therearound, serves to become wedged radially outwardly to prevent withdrawal of the film during use. Hultgren U.S. Pat. No. 2,954,941 granted Mar. 4, 1960 discloses a threading space having a single post therein through which film is threaded into the threading space around the reverse-direction post and back outwardly to be pressed by other reeled-on portions of the film against the free-end thereby locking the free-end against the outer-core surface of the reel. Also there is Hertel U.S. Pat. No. 3,982,709 that discloses a core-threading space having a reverse-direction upwardly extending post therein around which the film is threaded and carried in the reverse direction, in order to bind the surface thereof against the inner core outwardly facing wall. Also there is the Schankler U.S. Pat. No. 4,540,134 granted Sep. 10, 1985 that discloses a film reel having film-threadable space in which it is required that inwardly-directed posts inwardly-directed from the inner surface of the outer core wall opposes squared right-angular points of the inner core wall, with small spaces defined therebetween, and having also an upwardly extending reverse-direction post such that the film is threadable through the free space and the narrow spaces and around the reverse-direction post and back again through the spaces adjacent the right-angle corners to thereby eventually anchor the film-end.
A number of problems and disadvantages arise from the structures and arrangements of the prior art typically represented by the above-noted patents such as follow. Time is a valuable commodity for persons and companies constituting industry that utilize the film reels of the type to which this invention and the above-noted prior art are directed, such that narrow passages and complicated configurations and/or arrangements requiring time-consuming care and caution in the threading thereof are not only economically unfeasible, but practically worthless because no one in industry wants to nor will use them.
Also a common misconception is that the film-end retaining ability of a core is directly proportional to a major degree to a number of different configurations and grooves through which the film has to be threaded. In fact, in actual parctice, such does not prove to be true, the film end in a number of instances not being securely anchored--which in turn results in improper or faulty drawing or winding of the feed-film during the process of the reel-mounting of the film during its use from a feed-reel.
In order to achieve certain purported film-threading and film-anchoring advantages, there is considerable free space between inner and outer core wall structures, resulting in a common problem of likelihood of shearing of the outer reel structure from the inner core structure mounted on a winding spindle because of the major amount of torque imparted by the driven spindle driving the inner core structure, as compared to inertia of the outer reel structure that is pulling onto the reel the anchored film.
It has moreover been recently discovered that for computer-utilized reels, for example, on which the film is repeatedly run back and forth to and from the mounted end thereof, the sudden and repeated alternate forward and reverse actions of or on the reel results in a buckling or kick-back on the end-portion of the film that is threaded retainably within the core of the reel, with a result of the threaded film-end working-loose and eventually becoming disengaged from the reel core.